never mind - I have found the issue :
Under that 'add variables to pages' section - step 3 for the update page -
This is kinda misleading - I interpreted as insert a new update for table items -NOT as what you wanted - which was open the already existing update record for table items -
Mainly because the server behavior window does not fully match - mine looks like this:
Update Record (Update_Basic_Default, db_waMusic, items)
-- step 3 says - Open the Update Record (items) Server Behavior
Because of my server behavior window sizing, the items bit was not visible - indicating to me that it did not exist and that I needed to add it. -- Just a note though that when I finally did figure it out - there was no go to after insertion field listed for this update - and deleting that seems to be the whole point of the step. It is possible in my debugging and attempts though that I overwrote this - so I will wipe the site and start again, but I bet you it will work better. This does explain some of my noted issues though - like why am I using dreamweavers record update and not yours(WA) - because I am not supposed to be adding another insert at all - just opening the one already there.
I still wonder about the new updates that I was not notified about - but I guess it is my responsibility to check back in from time to time to look for new updates.
I also still and will always gripe about that captcha element - it makes getting this posted very difficult.
And hopefully I may have given you some more info about that double header send issue if you have not resolved it - but this could have been generated by forcing another update record insert on top of your update code - Which is what I did.
Sorry to anyone that wasted the time reading that whole bit -
I hope you read this one FIRST.